<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>响应式</title>
    <link rel="stylesheet" href="css/xiangyingshi.css">
</head>
<body>
<div class="container">
    <div class="col">网页的左侧</div>
    <div class="col">网页的中间</div>
    <div class="col">网页的右侧</div>
</div>
</body>
</html>